The move was made in reaction to restricted free agent Greg Stiemsma’s decision to sign an offer sheet to join the Minnesota Timberwolves.

Although they picked up Jared Sullinger and Fab Melo in the 2012 NBA Draft, the Celtics had to part with promising big man JaJuan Johnson in a sign-and-trade with the Houston Rockets that to bring wing Courtney Lee to Boston.

Collins, an 11-year veteran out of Stanford, played the last three seasons as a reserve center behind Al Horford for the Atlanta Hawks.

Never known for his offense, Collins averages only 3.8 points for his career. What he will offer is a defensive-minded option off the bench for the Celtics. Collins’ six fouls won’t hurt, either.